NRG Stadium Blue Lot Suite Parking

Hello, going to Houston & NRG stadium for the first time with a friend. We have suite tickets provided by employer, but we have to buy our own parking. The parking will be reimbursed by HR on submission of receipt.

I see that suite parking are Blue lots 17 & 18 and Green lot 28. My question is how to buy this parking? Are these lots reserved for suite ticket holders? If I buy a blue lot parking on ticketmaster, can I park in either lot 17 or 18 after presumably some staff checks that I have a suite ticket? Or do I need to buy parking specifically for lots 17 or 18? Ticketmaster is saying "This section is unreserved general admission" when I click on the blue suite lots and won't let me buy anything. I don't know what that means. Regular blue lot is going for $50. Similar story for Green lots. I can buy regular green lot but not the green suite lot 28.

Also, is parking by person or car? For two people, do I need to buy 2 tickets for parking or just 1 ticket for the whole car from ticketmaster?